MP4 to M4R -- convert mp4/mpeg4 to m4r format
Change MP4 to M4R format with MP4 to M4R Converter
Specially designed for iPhone users, MP4 to M4R Converter can convert almost all mainstream video/audio formats including AVI, MPEG, WMV, DivX, MP4, H.264/AVC, AVCHD, MKV, RM, MOV, XviD, 3GP, WMA, WAV, RA, M4A, MP3 to M4R iPhone ringtone, and transfer the converted M4R ringtone to iPhone directly without iTunes after conversion if you want. For iPod users, it is absolutely the best choice.
Guide: how to change mp4 to m4r
One. You need install the Converter in your pc and run it. Click PC to iPhone button get access to the ringtone maker interface.

Two. To add a file you want to convert into the software by clicking "Add File" button. Reset the start time and end time to exact a clip you like. You can drag the two sliders or change the number to make it. Then click Play button to pre-listen to it.

Three. Go to Local Output File tag to reset the destination folder to save the converted file by clicking "Browse" button.
Four. Click "Import" to activate the software. It will automatically work.

The conversion progress window will tell you the conversion status.
Come on to try this MP4 to M4R Converter. It will have your iPhone different from others and bring you a more perfect iPhone.